酱油选育菌种制曲条件的优化研究

Optimization on Koji-making Conditions for the Bred Strain from Soy Sauce

文章利用选育的米曲霉A3-U12优良菌株,采用正交试验设计方案,优化浸豆时间、蒸料时间、制曲时间等制曲工艺参数。结果表明:影响蛋白酶活力的因素主次顺序为浸豆时间>蒸料时间>制曲时间,较优水平为浸豆时间3h、蒸料时间30min、制曲时间40h;糖化酶活力的因素主次顺序为蒸煮时间>浸豆时间>制曲时间,较优水平为浸豆时间3h、蒸料时间30min、制曲时间36h。通过验证试验,在浸豆时间3h和蒸料时间30min的条件下,蛋白酶活力在40h时达到了最大值1435.52U/g干曲,糖化酶活力达到了936.73U/g干曲。

Based on the analysis of major factors of soy sauce koji making,the major parameters including soybean soaking time,steaming time and koji making time are optimized using orthogonal array design during koji making for soy sauce fermented by Aspergillus oryzae A3-U12.The results show that the importance order of koji making factors affecting the protease activity is soybean soaking timesteaming timekoji making time and the optimum conditions for the highest protease activity are as follows：soybean soaking time is 3 h,steaming time is 30 min and koji making time is 40 h.The importance order of koji making factors affecting glucoamylase activity is steaming timesoybean soaking timekoji making time and the optimum conditions for the highest protease activity are as follows：soybean soaking time is 3 h,steaming time is 30 min and koji making time is 36 h.Furthermore,based on the results of orthogonal test,the verification test is preformed to determine the optimal conditions for koji making.The results indicate that when soybean soaking time is 3 h,steaming time is30 min and koji-making time is 40 h,the protease activity and glucoamylase activity reach 1435.52,936.73 U/g dry koji respectively.